This invention relates generally to a device for mounting on a wheel mounted self-propelled irrigation sprinkler, and more particularly, but not by way of limitation, to a ramp device used in reducing wear on trojan bar dogs and wheel lugs, which are a part of the irrigation sprinkler equipment.
Heretofore, wheel mounted self-propelled irrigation sprinkler systems have been driven by water pressure driving a hydraulic water pump mounted on a tower frame. The hydraulic water pump through mechanical linkage drives a horizontally mounted trojan bar. The bar includes trojan bar dogs mounted at each end thereof. The trojan bar dogs engage wheel lugs which are mounted along the sides of wheels. The wheels support the tower frame and propel the irrigation sprinkler across the ground surface. During the drive stroke of the trojan bar, the trojan bar dogs contact one of the wheel lugs mounted on the wheels and drives the wheels forward until the trojan bar reaches the end of the drive stroke. At this point, the trojan bar starts its return stroke and the trojan bar dog disengages the wheel lugs and move rearwardly riding upwardly and over adjacent wheel lugs until the return stroke is completed. The direction of the trojan bar is reversed and the drive stroke starts again with the trojan bar dog engaging the adjacent wheel lugs and the pattern is repeated.
During the return stroke of the trojan bar, and after the trojan bar dogs have disengaged themselves from the wheel lugs, the trojan bar dogs ride over the adjacent wheel lugs and wear against the top surface of the wheel lugs. This contact between the dogs and wheel lugs causes premature wear of the bottom surface of the dogs and the top surface of the wheel lugs. This wear continues until the dogs and wheel lugs are sufficiently worn so that the dogs no longer engage the wheel lugs during the drive stroke or the dogs bind on the wheel lugs, thereby stopping the travel of the irrigation sprinkler.
The subject invention provides a ramp device used in conjuction with a wheel mounted self-propelled irrigation sprinkler which eliminates trojan bar dog and wheel lug wear.